Dental articulator



I. NAKAHA'RA.

DENTAL ARTICULATOR; APPLICATION FILED SEPT. 14 1918.

Patented May 25, 1920.

UNITED STATES ICHIGORO NAKAHARA, 0F TOKYO, JAPAN.

DENTAL ARTICULATOR.

Specification of Letters Patent.

Patented May 2."), 1920.

Application filed September 14,1918. Serial No. 254,100.

Tocll whom it may concern;

.Be it known that I, Iomeono NA'KAHARA, dentist, a subject of .thellmperor of Japan, and a resident of No. 67 E2Chome, Iida- Machi, .Kojimachi-Ku, Tokyo, Empire of Japan, have invented a new and useful. I m provement in Dental Articulators, of which the following is a specification.

This invention relates to improvements in dental articulators of that class in which the aw members have what is known as the anatomical adjustment with relation to each other tofacilitate the perfect production of the dentures.

One object of the invention is to effect improvements in the construction of the articulator to enable the upper jaw mold to be openedor closed to the desired extent, to be retained at any desired opened position, and further to enable the movement of the supporter of the upper jaw mold to be restricted to such an extent as to conform exactly with the condyle of the jaws of the patient, and thereby prevent the dentist from making mistakes in the articulation of the artificial teeth.

Another object of the invention is to effect improvements in the construction of the articulator whereby means are provided for holding the upper jaw mold in normal position while the models are being tried in the mouth of the patient.

With the above and other objects in view my invention consists in the construction, combination and arrangement of. devices hereinafter described and claimed.

In the accompanying drawings- Figure 1 is a plan view of my improved dental articulator.

Fig. 2 is a side elevation of the same.

Fig. 3 is an elevation showing a modified construction of the same.

The lower loop 6 which supports the model 19 of the lower jaw is secured as at 24 to a base 25, which is provided at the center with a vertical standard 26. A post 10 rises from saidstandard and is non-circular in cross section.

An arm 12 has a correspondingly shaped opening through which the post extends and is vertically movable on the post and secured thereto by a screw 27.

A relatively fixed tubular beam 1 has a a centrally located boss 1 on its rear side,

said boss having an opening through which the post .10 extends and being provided with a set screw whereby the said beam may be fixedly secured at any required vertical adjustment. liars A, A, project from the ends of said relatively fixed beam and are adjustably secured in the bore thereof by means of set screws 1, respectively. A spring 11, which consists of successively acting leaves 29, 30, secured at the center to the boss 1', the leaves of said spring diverging toward their ends.

L-shaped blocks 3, 3. are respectively secured to the outer ends of the bars A, A, by means of set screws 4, il, as shown. Said blocks are respectively provided in their outer sides with grooves 2, 2, and are also respectively provided at their front ends with adjusting screws 5, 5, which enter said grooves and enable their effective length to be varied.

The upper loop 6, which supports the model 20 of the upper jaw is secured as at 31 to a movable tubular beam 7, which is preferably and is here shown as rectangular in cross-section.

Substantially L-shaped arms 17, 17, have their inner ends adjustably secured in the ends of the movable tubular beam by means of set screws D, D. The forwardly extending ends of said arms are respectively provided with segmental disks 8, 8, against which the ends of the spring 11 frictionally bear, said disks having inwardly extending pins 9, 9', respectively, which enter the grooves of the blocks 3, 3, and hence the movable, upper mold-carrying beam is pivotally and adjustably mounted on the relatively fixed beam 1, both for vertical pivotal movement and for lateral angular movement.

The movable beam 7 has at its center a rearwardly extending arm 7, and a spring 13 is arranged between. the arms 12 and 7 and serves to retain the upper jaw mold 20 in position. A screw 32 is arranged in the said spring and engages a threaded opening in the arm 12. The spring 11 by its engagement with the disks 8, 8, presses the movable, upper mold carrying beam constantly forwardly and keeps the same in position, while Permitting the required adjustments thereof.

In the modified form of the invention shown in Fig. 3, a spring 14 is substituted for the spring 13, and is suspended from an arm 18 which is vertically adjustable on the post 10 and may be secured at any required adjustment by means of a set screw 18.

The operation which is very simple but efl'ective is as follows:

Before the models of the teeth are taken out from the patientsmouth the dentist marks upon the lower model the line actu ally traced or registered by the upper model. lVhen the upper and lower models 22, 21, are taken out from the mouth and attached to their respective jaw molds 20, 19, the dentist then proceeds to determine the position of the upper model by adjusting the screws 5, 5', until the movement of the upper supporter 6 coincides with the lines previously marked by the dentist upon the lower model of the teeth, thus preventing him from taking other than a correct bite preparatory to the preparation of an artificial tooth.

\Vhat I claim is '1. In a dental articulator, an upper jaw mold holder comprising a relatively fixed member, a movable member connected thereto, for vertical pivotal movement and also for lateral rocking movement, and adj usting means carried by the relatively fixed men"- ber, to control and determine the extent of such. lateral rocking movement.

. 2. In a dental articulator, an upper jaw mold holder comprising a relatively fixed member, blocks connected to the ends thereof and adjustable with relation thereto, a.

movable member connected to said blocks pivotal movement and also for lateral roeking movement of said movable member, said arms having segmental. disks, adjusting means to control and determine the extent of such lateral rocking movement ot said movable member, and a spring pressing :forwardly against the peripheries o'l said disks.

4. In a dental articulator, an upper jaw mold holder comprising a relatively fixed member, a movable member connected thereto for vertical pivotal movement and also for lateral rocking movement, adjusting means to control and determine the extent of such lateral rocking movement, and a spring to elastically retain the upper jaw mold in position.

In testimony whereof I. allix my signature. in presence of two witnesses.

ICHIGORO NA KA HA RA, \Vitnesses I'IARVEY l. (.luriuANs, HANrranx Yxsnaunm. 

